#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dirent.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>

#define MAX_PATH_LENGTH		512
#define MAX_FILE_EXTENSION	9

unsigned long visit_dirs = 0;
unsigned long visit_files = 0;

void listdir(char *path){
    DIR 		*ptr_dir;
    struct dirent 	*dir_entry;
    int 		i = 0;
    char		*child_path;
    char		*file_path;

    child_path = (char*)malloc(sizeof(char)*MAX_PATH_LENGTH);
    if(child_path == NULL){
        printf("allocate memory for path failed.\n");
        return;
    }
    memset(child_path, 0, sizeof(char)*MAX_PATH_LENGTH);

    file_path = (char*)malloc(sizeof(char)*MAX_PATH_LENGTH);
    if(file_path == NULL){
        printf("allocate memory for file path failed.\n");
        free(child_path);
        child_path = NULL;
        return;
    }
    memset(file_path, 0, sizeof(char)*MAX_PATH_LENGTH);

    ptr_dir = opendir(path);
    while((dir_entry = readdir(ptr_dir)) != NULL){
        if(dir_entry->d_type & DT_DIR){
              
            if(strcmp(dir_entry->d_name,".") == 0 ||
               strcmp(dir_entry->d_name,"..") == 0){
                continue;
            }

            sprintf(child_path, "%s/%s", path, dir_entry->d_name);
            printf("[DIR]%s\n", child_path);

            visit_dirs++;

            listdir(child_path);
        }

        if(dir_entry->d_type & DT_REG){
            sprintf(file_path, "%s/%s", path, dir_entry->d_name);
            printf("[FILE]%s\n", file_path);
            visit_files++;
        }
    }

    free(child_path);
    child_path = NULL;

    free(file_path);
    file_path = NULL;
}

int main(int argc, char* argv[]){
    if(argc == 2){
        listdir(argv[1]);
        printf("Total DIR: %ld, Total FILE: %ld\n", visit_dirs, visit_files);
    }else{
        printf("Usage: listdir <dir>\n");
        return -1;
    }

    return 0;
}
